deckcraft/crates/format/src/lib.rs

263 lines
10 KiB
Rust

//! The native `.deckcraft` format: a zip holding `presentation.json` (the model, minus media
//! bytes), `media/<id>` files with the embedded media, and `mimetype`. Readers ignore unknown
//! fields, so newer files open in older builds with what those builds understand.
#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
#![forbid(unsafe_code)]
use std::io::{Cursor, Read, Write};
use std::sync::Arc;
use deckcraft_model::text::{Paragraph, TextBody};
use deckcraft_model::{LayoutType, Presentation, defaults};
pub const MIMETYPE: &str = "application/vnd.storyteller.deckcraft+zip";
/// Files written before the SlideCraft → DeckCraft rename (`.slidecraft`) are still read.
pub const LEGACY_MIMETYPE: &str = concat!("application/vnd.storyteller.", "slide", "craft+zip");
pub const EXTENSION: &str = "deckcraft";
/// Format version written into the manifest.
pub const VERSION: u32 = 1;
/// Largest entry we will inflate (guards against zip bombs).
const MAX_ENTRY: u64 = 2 << 30;
#[derive(Debug, thiserror::Error)]
pub enum FormatError {
#[error("not a DeckCraft file: {0}")]
NotOurs(String),
#[error("damaged file: {0}")]
Damaged(String),
#[error("write failed: {0}")]
Write(String),
}
pub type Result<T> = std::result::Result<T, FormatError>;
#[derive(serde::Serialize, serde::Deserialize)]
struct Manifest {
format: String,
version: u32,
generator: String,
presentation: Presentation,
}
/// Serialize a presentation.
pub fn save(p: &Presentation) -> Result<Vec<u8>> {
let mut buf = Cursor::new(Vec::new());
{
let mut z = zip::ZipWriter::new(&mut buf);
let stored = zip::write::SimpleFileOptions::default().compression_method(zip::CompressionMethod::Stored);
let deflate = zip::write::SimpleFileOptions::default().compression_method(zip::CompressionMethod::Deflated);
let w = |e: zip::result::ZipError| FormatError::Write(e.to_string());
z.start_file("mimetype", stored).map_err(w)?;
z.write_all(MIMETYPE.as_bytes()).map_err(|e| FormatError::Write(e.to_string()))?;
let m = Manifest {
format: "deckcraft".into(),
version: VERSION,
generator: format!("DeckCraft {}", env!("CARGO_PKG_VERSION")),
presentation: p.clone(),
};
let json = serde_json::to_vec(&m).map_err(|e| FormatError::Write(e.to_string()))?;
z.start_file("presentation.json", deflate).map_err(w)?;
z.write_all(&json).map_err(|e| FormatError::Write(e.to_string()))?;
for item in &p.media {
if item.link.is_some() && item.data.is_empty() {
continue;
}
// Already-compressed media is stored, not deflated again.
let opts = if is_compressed(&item.content_type) { stored } else { deflate };
z.start_file(format!("media/{}", item.id.0), opts).map_err(w)?;
z.write_all(&item.data).map_err(|e| FormatError::Write(e.to_string()))?;
}
z.finish().map_err(w)?;
}
Ok(buf.into_inner())
}
fn is_compressed(ct: &str) -> bool {
ct.starts_with("image/jpeg")
|| ct.starts_with("image/png")
|| ct.starts_with("video/")
|| ct.starts_with("audio/mpeg")
|| ct.starts_with("audio/mp4")
|| ct.contains("zip")
}
/// Does this look like a `.deckcraft` file?
pub fn sniff(bytes: &[u8]) -> bool {
bytes.starts_with(b"PK") && [MIMETYPE, LEGACY_MIMETYPE].iter().any(|m| bytes.windows(m.len()).take(200).any(|w| w == m.as_bytes()))
}
fn read_entry(z: &mut zip::ZipArchive<Cursor<&[u8]>>, name: &str) -> Result<Vec<u8>> {
let f = z.by_name(name).map_err(|e| FormatError::Damaged(format!("{name}: {e}")))?;
if f.size() > MAX_ENTRY {
return Err(FormatError::Damaged(format!("{name} is too large")));
}
let mut out = Vec::with_capacity(f.size().min(64 << 20) as usize);
f.take(MAX_ENTRY).read_to_end(&mut out).map_err(|e| FormatError::Damaged(format!("{name}: {e}")))?;
Ok(out)
}
/// Read a presentation.
pub fn load(bytes: &[u8]) -> Result<Presentation> {
let mut z = zip::ZipArchive::new(Cursor::new(bytes)).map_err(|e| FormatError::NotOurs(e.to_string()))?;
let json = read_entry(&mut z, "presentation.json").map_err(|_| FormatError::NotOurs("no presentation.json".into()))?;
let m: Manifest = serde_json::from_slice(&json).map_err(|e| FormatError::Damaged(e.to_string()))?;
if m.format != "deckcraft" {
return Err(FormatError::NotOurs(m.format));
}
let mut p = m.presentation;
for item in &mut p.media {
if let Ok(data) = read_entry(&mut z, &format!("media/{}", item.id.0)) {
item.data = Arc::new(data);
}
}
repair(&mut p);
Ok(p)
}
/// Make a loaded presentation safe to edit: a master exists, every slide's layout exists,
/// ids are unique, tables are rectangular.
pub fn repair(p: &mut Presentation) {
if p.masters.is_empty() {
let fresh = defaults::blank_presentation(p.slide_size, Default::default(), false);
p.masters = fresh.masters;
}
p.fix_next_id();
let first_layout = p.masters.first().and_then(|m| m.layouts.first()).map(|l| l.id).unwrap_or_default();
let mut seen = std::collections::HashSet::new();
for i in 0..p.slides.len() {
let needs_layout = p.slides.get(i).is_some_and(|s| p.layout(s.layout).is_none());
let dup = p.slides.get(i).is_some_and(|s| !seen.insert(s.id));
if needs_layout || dup {
let new_id = if dup { Some(deckcraft_model::SlideId(p.alloc_id())) } else { None };
if let Some(s) = p.slides.get_mut(i) {
let s = Arc::make_mut(s);
if needs_layout {
s.layout = first_layout;
}
if let Some(id) = new_id {
s.id = id;
}
}
}
}
if !(p.slide_size.width.is_finite() && p.slide_size.width >= 1.0 && p.slide_size.height.is_finite() && p.slide_size.height >= 1.0) {
p.slide_size = defaults::WIDE;
}
p.slide_size.width = p.slide_size.width.min(4000.0);
p.slide_size.height = p.slide_size.height.min(4000.0);
}
/// Outline text: one slide per unindented line; tab-indented lines become body bullets at their
/// level (Insert ▸ Slides from Outline, View ▸ Outline copy).
pub fn outline_to_slides(p: &mut Presentation, text: &str) -> usize {
let Some(lay) = defaults::layout_of_kind(p, LayoutType::TitleAndContent) else { return 0 };
let mut made = 0;
let mut cur: Option<deckcraft_model::Slide> = None;
let flush = |p: &mut Presentation, s: Option<deckcraft_model::Slide>, made: &mut usize| {
if let Some(s) = s {
p.slides.push(Arc::new(s));
*made += 1;
}
};
for raw in text.lines() {
if raw.trim().is_empty() {
continue;
}
let tabs = raw.chars().take_while(|c| *c == '\t').count();
let spaces = raw.chars().take_while(|c| *c == ' ').count() / 2;
let level = tabs.max(spaces);
let line = raw.trim().trim_start_matches(['-', '*', '•']).trim();
if level == 0 {
flush(p, cur.take(), &mut made);
let mut s = defaults::new_slide(p, lay);
if let Some(t) = s.shapes.first_mut() {
t.text = Some(TextBody::from_text(line));
}
cur = Some(s);
} else if let Some(s) = cur.as_mut()
&& let Some(body) = s.shapes.get_mut(1)
{
let tb = body.text.get_or_insert_with(TextBody::default);
let mut para = Paragraph::new(line);
para.level = (level - 1).min(8) as u8;
tb.paragraphs.push(para);
}
}
flush(p, cur, &mut made);
made
}
/// The deck as outline text (titles unindented, body paragraphs tab-indented by level).
pub fn slides_to_outline(p: &Presentation) -> String {
let mut out = String::new();
for s in &p.slides {
out.push_str(&s.title());
out.push('\n');
for sh in &s.shapes {
if sh.ph_type().is_some_and(|k| k.is_title()) {
continue;
}
if let Some(t) = &sh.text {
for para in &t.paragraphs {
if para.is_empty() {
continue;
}
for _ in 0..=para.level {
out.push('\t');
}
out.push_str(&para.text().replace('\u{b}', " "));
out.push('\n');
}
}
}
}
out
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn roundtrip_with_media() {
let mut p = Presentation::default();
let id = p.add_media("a.png", "image/png", vec![1, 2, 3, 4]);
let bytes = save(&p).unwrap();
assert!(sniff(&bytes));
let q = load(&bytes).unwrap();
assert_eq!(q.slides.len(), p.slides.len());
assert_eq!(q.media(id).map(|m| m.data.as_slice()), Some(&[1u8, 2, 3, 4][..]));
assert_eq!(serde_json::to_value(&q.slides).unwrap(), serde_json::to_value(&p.slides).unwrap());
}
#[test]
fn garbage_is_an_error_not_a_panic() {
assert!(load(b"").is_err());
assert!(load(b"PK\x03\x04garbage").is_err());
assert!(load(&[0u8; 1000]).is_err());
let mut b = save(&Presentation::default()).unwrap();
let n = b.len();
b.truncate(n / 2);
assert!(load(&b).is_err());
}
#[test]
fn repair_fixes_missing_layout_and_size() {
let mut p = Presentation::default();
Arc::make_mut(&mut p.slides[0]).layout = deckcraft_model::LayoutId(99999);
p.slide_size.width = f64::NAN;
repair(&mut p);
assert!(p.validate().is_empty());
assert_eq!(p.slide_size.width, 960.0);
}
#[test]
fn outline_roundtrip() {
let mut p = defaults::blank_presentation(defaults::WIDE, Default::default(), false);
let n = outline_to_slides(&mut p, "Intro\n\tPoint one\n\t\tSub point\nSecond\n\tMore");
assert_eq!(n, 2);
let o = slides_to_outline(&p);
assert!(o.contains("Intro\n\tPoint one\n\t\tSub point\nSecond"), "{o}");
}
}